A scanner is provided with a main body, hinge, cover member, and plurality of sets of pins and pin holes. The main body includes a transparent plate on the top surface for placing a document. The hinge connects the main body and the cover member. The cover member rotates between an opened and closed state with respect to the main body. The cover member has a bottom surface, which contacts the top surface of the main body when closed. The pins are fanned on either the top surface of the main body or the bottom surface of the cover member, while the pin holes are formed on the opposing surface. The plurality of sets adjusts a positional relationship between the main body and the cover member in the closed state.